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Drought stress is one of the major threats to food security in the climate change scenario. Reducing the deleterious impacts of drought stress on the productivity of cereal crops is crucial. Hence, limited information has been available about the effect of the combined use of plant growth regulators and mineral fertilisers on promoting drought tolerance in maize seedlings. In this study, a pot experiment was carried out to evaluate the potential of sole or combined application of silicon (Si) and putrescine (Put) to mitigate the detrimental effects of drought on maize. The experimental treatments were, i.e. control (CK), water spray, 4.0 mmol Si, 0.5 mmol Put, and 4.0 mmol Si + 0.5 mmol Put on maize crop grown at two different water-holding capacity levels (80% well-water condition and 40% drought stress). The experiment was arranged in a complete randomised design with factorial arrangements having three replications. Exposure of maize plants to drought stress at the reproductive phase (VT-tasseling) reduced the photosynthetic pigments, including chlorophyll a, chlorophyll b and chlorophyll a + b, relative water contents, leaf area, yield and yield attributes. However, foliar application of Si and Put individually and Si + Put dramatically reduced these negative effects by improving photosynthetic pigments, relative water contents, and activities of enzymatic antioxidant defence. Drought stress-induced lipid peroxidation in the form of more production of malondialdehyde content, hydrogen peroxide and electrolyte leakage significantly declined due to the combined application of Si and Put compared to the respective control. Drought stress boosted the activities of key enzymatic antioxidants (catalase, superoxide dismutase, peroxidase, and ascorbate peroxidase) irrespective of the treatment application. Moreover, it was noted that the accumulation of osmolytes (proline and soluble protein) contents was increased by the combined application of Si and Put. Under drought stress conditions, combined foliar application of Si and Put considerably improved 22.70% cob length, 12.77% number of grains per cob, and 18.30% 100-grain weight, which ultimately enhanced maize's 10.29% grain yield. From the current study's findings, it was concluded that a combined foliar spray of silicon and putrescine at the reproductive phase is an effective strategy to enhance the maize yield in drought-prone areas.

Drought stress is one of the major threats to food security in the climate change scenario. Reducing the deleterious impacts of drought stress on the productivity of cereal crops is crucial. Hence, limited information has been available about the effect of the combined use of plant growth regulators and mineral fertilisers on promoting drought tolerance in maize seedlings. In this study, a pot experiment was carried out to evaluate the potential of sole or combined application of silicon (Si) and putrescine (Put) to mitigate the detrimental effects of drought on maize. The experimental treatments were, i.e. control (CK), water spray, 4.0 mmol Si, 0.5 mmol Put, and 4.0 mmol Si + 0.5 mmol Put on maize crop grown at two different water-holding capacity levels (80% well-water condition and 40% drought stress). The experiment was arranged in a complete randomised design with factorial arrangements having three replications. Exposure of maize plants to drought stress at the reproductive phase (VT-tasseling) reduced the photosynthetic pigments, including chlorophyll a, chlorophyll b and chlorophyll a + b, relative water contents, leaf area, yield and yield attributes. However, foliar application of Si and Put individually and Si + Put dramatically reduced these negative effects by improving photosynthetic pigments, relative water contents, and activities of enzymatic antioxidant defence. Drought stress-induced lipid peroxidation in the form of more production of malondialdehyde content, hydrogen peroxide and electrolyte leakage significantly declined due to the combined application of Si and Put compared to the respective control. Drought stress boosted the activities of key enzymatic antioxidants (catalase, superoxide dismutase, peroxidase, and ascorbate peroxidase) irrespective of the treatment application. Moreover, it was noted that the accumulation of osmolytes (proline and soluble protein) contents was increased by the combined application of Si and Put. Under drought stress conditions, combined foliar application of Si and Put considerably improved 22.70% cob length, 12.77% number of grains per cob, and 18.30% 100-grain weight, which ultimately enhanced maize's 10.29% grain yield. From the current study's findings, it was concluded that a combined foliar spray of silicon and putrescine at the reproductive phase is an effective strategy to enhance the maize yield in drought-prone areas. [ABSTRACT FROM AUTHOR]

One of the main objectives of the states located in the territory of arid regions is the timely obtaining solid and exhaustive data, the forecasts connected with the climatic phenomena, allowing to provide the timely organization of works on safety and prevention of possible damage to agriculture and in general all national economy. This task can be solved only in the presence of well adjusted, system of collecting, processing and implementation of information. For ensuring food security of the country it is necessary to provide the integrated control system of water resources at timely coordination of all stages of regulation on the basis of multiplefactor monitoring of indicators.The increasing deficiency of water resources in basins of the cross-border rivers of the arid region of the republic demands introduction of the new scheme of management which would allow their use in the conditions of limitation.Due to the formation of the new independent states need of improvement of the existing organizational forms of ownership and water resources management of the cross-border rivers which will be proved on rules of international law and the best practice of cooperation pools when sharing taking into account the interests of the adjacent countries of the region is caused. The main priority direction of the arid region of the republic is development of long-term programs, proved on a package of measures and actions for water economy, maintaining her quality and increase in an ecological situation of water management systems.Now each country develops own strategies of water use which leads to strengthening of the competition for water, sharpening of deficiency of water and environmental problems, both on interstate, and at the regional level. Further, the issue of ensuring food security in the conditions of impact of climate change on agriculture is resolved. The existing risks connected with climate changes and ways of adaptation of agricultural production have been defined.The main national policy of the republic is aimed at ensuring the food security with the balance of production. Considering features of the region and the available restrictions as: existence of the irrigated lands, their efficiency, limitation of water resources and their effective use has to be proved on universal introduction of water-conservation technologies of irrigation when carrying out complex reconstruction of irrigating systems and the principles of the integrated use of water resources.

The article deals with the consequences of global climatic changes on the state of Ukrainian Danube region agrolandscapes. The influence of weather climatic conditions on change of water balance of the regional ecological systems was studied by definition of three main indicators: evaporability, deficiency of water consumption and moistening coefficient. Experimental information was given according to supervision of Danube Hydrometeorological Observatory (Izmail, Ukraine). In comparison with the statistics of weather conditions for 1961-1990 and 1991-2000 the climatic situation in 2001-2012 testifies to significant increase in an evaporability (19, 5 %) and deficiency of water consumption of the soil (41, 9 %). As a result some changes of agrolandscapes were noticed in the region, connected with mass emergence of weeds, which are atypical for the region: Ambrosia artemisifolia L. Lactuca tatarica L, Anisantha tectorum Nevski, Cyclachaena Xantifolia L. etc. Due to the high competitive capacity of weed plants, they began to occupy in the cultivated cultural plants a dominant position that led to decrease of fertility of soils and crops. Thus agrolandscapes traditionally created on arable lands became now unstable and are in great need in their arrangement.